For User Equipment (UE) operating in a wireless communication system such as a Long Term Evolution (LTE) system, the UE is required to have the most up to date versions of the Master Information Block (MIB) and System Information Blocks (SIB) before the UE can transmit within the wireless system. For example, acquiring MIB and SIBs is typically done during initial power up of the UE, when changes in the cell being used for wireless communication occur, or when the MIB or SIB changes.
As is known, for a UE to access the evolved Node B (eNB) two different SIBs are required, namely SIB1 and SIB2. SIB 1 carries information relating to cell access related information, for example cell selection information and scheduling information. As is known, SIB 1 uses a fixed schedule for transmission by the eNB with a periodicity of 80 ms and repetitions made within 80 ms.
Currently, there is a focus on providing improved power consumption for a UE, in particular for machine-to-machine (M2M) wireless devices, or Machine Type Communication (MTC) devices, which may have significantly different operating requirements from typical user devices. For example, M2M devices such as wireless monitors or meters may only transmit relatively small amounts of data, possibly infrequently and possibly with high tolerance to latency, system acquisition times or the like.
For example, long sleep cycles for Power Saving Mode (PSM) are provided for in LTE release 12, wherein these long sleep cycles may exceed 2.5 seconds. Accordingly, a UE will potentially miss page notifications of changes to SIBs. As such, when a UE wakes up it is required to reconfirm that no MIB or SIB changes have occurred. Also as defined, SIB1 has a revision number for the UE to check thereby enabling a modified SIB1 to be identified.
Low power, low cost UE devices that are also able to work in low signal levels requiring coverage extension are desired. However, constraining these devices to receive the currently existing information messages (MIB and SIBs) requires these types of UE devices to receive more information than they need. Accordingly, unnecessary power is being used to receive and process these information messages that may not be necessary for their desired level of operation.
In light of the above power consumption concerns, proposals have been made for various scheduling and frequency restrictions to be placed on the existing system information transmissions. These types of restrictions are possible within the framework of the existing configurable scheduling options but may limit signalling information changes and signalling efficiency. Furthermore, with these types of restrictions, the timing of changes could affect the ability to communicate these changes to legacy devices served in a cell when they may be needed and also restrict the flexibility to efficiently schedule downlink communications by the eNB.
Therefore, there is a need for a method and apparatus for improving power consumption of a UE that is not subject to one or more limitations in the prior art.
This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present technology. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present technology.